Nonparametric Analysis of Clustered Multistate Processes.

clusteredMSM

Nonparametric analysis of clustered multistate process data.

clusteredMSM provides population-averaged transition probability estimates, pointwise confidence intervals, simultaneous confidence bands, and two-sample Kolmogorov-Smirnov-type tests for multistate process data with cluster-correlated observations. Estimation follows Bakoyannis (2021); two-sample inference for the cluster-randomized and independent-samples designs follows Bakoyannis & Bandyopadhyay (2022). Both rest on the working-independence Aalen-Johansen estimator with a cluster-bootstrap variance.

Unlike its predecessor (the clustered-multistate repository, which relied on the mstate package), clusteredMSM is self-contained (depending only on survival) and supports non-monotone multistate processes, including illness-death with recovery and other models with cyclic transitions.

Installation

# install.packages("devtools")
devtools::install_github("gbakoyannis/clusteredMSM")

After CRAN release:

install.packages("clusteredMSM")

A single function with a formula interface

clusteredMSM exposes one main function, patp(), modelled after survival::Surv():

library(clusteredMSM)

# Synthetic clustered illness-death-with-recovery data (40 subjects,
# 8 clusters); see ?example_msm.
data(example_msm)

# Define the transition structure (illness-death with recovery)
tmat <- trans_mat(list(c(2, 3), c(1, 3), integer(0)),
                  names = c("Healthy", "Ill", "Dead"))

# One-sample analysis: P(Ill at t | Healthy at 0)
fit <- patp(msm(Tstart, Tstop, Sstart, Sstop) ~ 1,
            data = example_msm, tmat = tmat,
            id = "id", cluster = "cluster",
            h = 1, j = 2, s = 0,
            B = 1000, cband = TRUE)
fit

If the formula's right-hand side has a grouping variable, patp() automatically estimates both group-specific curves AND tests their equality:

# Two-sample analysis (estimate + test in one call)
tt <- patp(msm(Tstart, Tstop, Sstart, Sstop) ~ treatment,
           data = example_msm, tmat = tmat,
           id = "id", cluster = "cluster",
           h = 1, j = 2, B = 1000)
tt

Loading your own data

The same example is shipped as a CSV under inst/extdata/, so you can mimic the typical workflow of reading a user-supplied file:

f <- system.file("extdata", "example_data.csv", package = "clusteredMSM")
mydata <- read.csv(f)
head(mydata)

Input data format

Each row of your data represents one mutually-exclusive time interval for one subject, with columns:

The column names are arbitrary — msm(...) and the id/cluster arguments tell the package which is which.

Censoring is encoded as Sstart == Sstop on the final row of a subject's record. Subjects in absorbing states have no row after them.

Within each subject, intervals must be: - Temporally contiguous:Tstop[k] == Tstart[k+1] - State contiguous:Sstop[k] == Sstart[k+1]

Validation is strict and informative — any violation triggers an error with a clear message.

Examples of valid input

Progressive illness-death (subject who got ill, then died):

Subject censored healthy:

Recovery (Healthy → Ill → Healthy → censored):

Core functions

References

Bakoyannis, G. (2021). Nonparametric analysis of nonhomogeneous multistate processes with clustered observations. Biometrics, 77(2), 533-546. doi:10.1111/biom.13327

Bakoyannis, G., & Bandyopadhyay, D. (2022). Nonparametric tests for multistate processes with clustered data. Annals of the Institute of Statistical Mathematics, 74(5), 837-867. doi:10.1007/s10463-021-00819-x

You can retrieve the BibTeX entries within R via toBibtex(citation("clusteredMSM")).

License

GPL-3